In moving picture coding, the quantity of information is generally reduced using redundancy of moving pictures in spatial and temporal directions. Here, a method using the redundancy in the spatial direction is represented by transform into frequency domain. A method using the redundancy in the temporal direction is represented by inter-picture prediction (hereinafter referred to as “inter prediction”) coding. In the inter prediction coding, when a current block to be coded included in a current picture to be coded is coded, at least one coded picture preceding or following the current picture in display time order are used as a reference picture. Then, a motion vector is derived through motion estimation of the current block with respect to the reference picture. Subsequently, the redundancy in the temporal direction is removed by calculating a difference between input image data of the current block and prediction image data of the current block resulting from motion compensation based on the derived motion vector (see Non Patent Literature (NPL) 1, for instance).